The disease beriberi is caused by a deficiency of which vitamin?

Beriberi is caused by a deficiency of thiamine, also known as vitamin B1. Thiamine is needed for enzymes that help cells use carbohydrates for energy, so severe deficiency can damage the nervous system, heart and other tissues.

The disease has two classic forms. Dry beriberi mainly affects the peripheral nerves and may cause weakness, pain, numbness and difficulty walking. Wet beriberi primarily affects the cardiovascular system, producing a rapid heartbeat, swelling and shortness of breath. Severe neurological thiamine deficiency can also cause Wernicke encephalopathy and Korsakoff syndrome.

Beriberi became especially associated with diets based heavily on polished white rice. Milling removes the nutrient-rich outer layers of rice, including much of its thiamine. Alcohol-use disorder, chronic digestive illness, dialysis and prolonged poor nutrition can also increase risk.

The disease helped establish the importance of vitamins in human health. Christiaan Eijkman found that unpolished rice protected chickens from a beriberi-like illness, and he later shared the 1929 Nobel Prize for Physiology or Medicine for work connected to the discovery of vitamins.